Processors

Information about CPUs, ALUs, and related technologies

Computers

Information and documentation on older computers

Compression

Information and documentation on compression algorithms, audio coding, and video coding

Games

Solutions or information related to games and puzzles

Math

Various topics in math, including prime numbers and pi

Cryptography

Crypto algorithms, message digest (hash) functions, and digital signature algorithms

Communication

Information on communication protocols, including newer VoIP protocols, as well as older protocols like XMODEM.